Busbars are used in electrical power distribution and particularly for distributing the electrical power to electrical switches that connect to subnets.
In case of medium to high voltage applications, with voltages of 1 kV and higher, two busbars cannot simply be connected to each other. The medium to high voltages generate an electrical field in between the busbars and in between the busbars and the earthed cabinet. The density of this electrical field should be kept as low as possible and under the acceptable limits, as otherwise flashover can occur. As a result any transition in a busbar and thus in any connection is currently made as fluent as possible to avoid areas of high field density.
Busbars are for example used in switchgear for connecting subnets to a main power supply. Switchgear typically has a housing through which three busbars run, one for each phase. Within each housing suitable switches are arranged for connecting or disconnection a panel of a subnet to the busbars.
In JP 2009 261215 a connector for connecting two conductor ends is described. An insulator body is arranged around the conductor ends and a vessel filled with a gas is enveloping the elements. EP 0175637 discloses an electrically conducting shield having a tubular shape. Both ends of the conductors are inserted into the shield and tightened by screws. EP 0789424 discloses a specific connector for conductors, which are provided with longitudinal grooves. The connector itself is provided with inner grooves to provide an electrically conducting connection between the connector and the conductor. A housing is furthermore arranged around the connector and the conductor ends, which housing could be filed with a gas. JP 9308023 discloses a connector for two conductors. The conductor ends are provided with flanges which are bolted together and a tubular shield is arranged around the connector. DE 2707592 relates to a connector which allows for misalignment of the conductor ends. The connector is a tubular element having two eccentric holes. By rotating the tubular element, the misalignment can be taken care of.
Because usually several subnets are connected to a main power supply, a number of panels are positioned next to each other and the busbars connect the adjacent panels to each other. In order to have a fluent and neat connection of the busbars of adjacent panels, the housings are aligned and set to height, such that the busbars are aligned as good as possible. Then the busbars are connected to each other by for example bolting a conductor to both free ends of aligned busbars.
Typically, when connecting busbars to each other, the free ends of the busbars are provided with large radii to ensure, that even if a small misalignment of the busbars occurs, the transition from one busbar to a next busbar is as fluent as possible avoiding areas of high electrical field density. To provide the large radii, the busbar free end has to be machined. This is a costly manufacturing step.
The alignment of the switchgear and the machining of the busbars to provide the required radii, take time and effort, resulting in high costs.